What does error e.oc indicate?

I may miss the point here. If the question is how to clear the error, page 57, item 4.7 Error Messages, of the KEB instruction manual may be of use. https://www.manualslib.com/manual/1293218/Keb-Combivert-F5.html?page=55#manual

Here is information about the error code:

KEB Error "E. OP"
ERROR overpotential (voltage)
1 Voltage in the DC-link cicuit is too high.
Occurs if the DC-link circuit voltage exceeds the permisible value.
Causes:
- poor controller adjustment (overshooting)
- input voltage too high
- interference voltages at the input
- deceleration ramp to short
- braking resistor defective or too small

Given the very technical nature of the KEB, I lean toward referring to the manufacturer's support. There are quite a number of KEB YouTube videos and a number of supporting documentations available on the web. Perhaps the following will be of use if not an entire misdirection: https://www.kebamerica.com/elevator-support/

https://www.kebamerica.com/products/f5-inverter/

Error. Over Current - Peak current exceeded
Possible causes:
Motor has a short - Phase to phase or phase to ground.
Motor cable damaged/defective.
Motor cables too long.
Acceleration/deceleration ramps too short.
Damaged output phase of inverter.
EMI

Error Over Current.

Disconnect motor leads at U/V/W terminals and run the inverter to determine if the problem is internal or external of the inverter.

If it is external then you are looking for a shorted winding in the motor or a shorted motor lead between the inverter and the motor.

Error. Over Current - Peak current exceeded

Possible causes:
Motor has a short - Phase to phase or phase to ground.
Motor cable damaged/defective.
Motor cables too long.
Acceleration/deceleration ramps too short.
Damaged output phase of inverter.
EMI

The KEB inverter does not have a "COM" error.

Where is this error being displayed?

Check your inverter baud rate, inverter address, communications cables and device that is being used to communicate.

It sounds like you may have a thermal issue causing the fault trigger of the E.OC error. This coould be an issue with the motor or the inverter getting too hot. Once the system trips into error it is allowed to cool a little and you can run again for a while.

What is the actual part# and serial # of the inverter that you are having problems with?

Since they system has been running, I would not suggest aultering the voltage/hz curves in the inverter because of an E.OC error.

E.OC is an over current error.

The inverter is sensing a short on the U/V/W terminals. This could be a shorted motor, motor leads and an internal short in the inverter.

Disconnect the motor leads from the inverter, and run the inverter as you normally would.

If the E.OC error does not occur the short is external of the inverter.
If the E.OC occurs, then the short is internal to the inverter.

E.puci During the initialization the power circuit could not be recognized as invalid.
E.puch power unit changed
power unit identification was changed, with a avalid power circuit this error can be reset by writting to SY.3. If the value displayed in SY.3 is written, only the power-cricuit dependent parameters are reinitialized. if any other value is written, then the default set is loaded . On some systems after writing SY.3 a power-On -Reset is necessary........
E.OC Overcurrent

i have a prblem in the F5 keb combivert it's show Error
E.OC & E.puci & E.Puch could you please advice us with the proper solution
thanks

Over temperature signal from motor temperature sensor. Error can only be reset once the display reads E.nOH. Causes:
*Resistor at terminal T1:T2 > 1650 ohms * Motor overloaded (getting hot) *Temperature sensor defective